and I still remember that Uke was jealous when Teasung smiled near his female business friend. At that point we knew that they loved each other

From the spoilers I read, the story is like this

Alpha and Uke both like each other, but the problem is that Alpha is Uke's uncle. they had that relationship until they had children, but Uke's mother didn't seem to approve of that because it was her own uncle. Finally, right after the birth, the uterus was lifted by the mother, when Uke realized he was asked where his son was, he said he was dead. Then I don't know how the story goes, he said Uke tried to kill himself but it didn't work, then Uke seemed to be depressed, stressed and had lost his memory. In the end he was put in a mental hospital, so all this time what Uke thought he was at the Omega trading place was actually just his 'hallucinations' when in fact he was still in a mental hospital, the problem was he had gone mad from stress. So there's no way he was bought by Alpha, it's true, he just brought it home with his daddy.
That's why at the beginning the Alpha asked who he was, Uke answered 'a foreigner' and the Alpha said again 'well let's start by assuming a foreigner'

I feel sorry for uke sis